[PATCH 41/42] block: do not use REQ_FLUSH for tracking flush support
From: <hidden>
Date: 2016-04-15 19:16:16
Also in:
dm-devel, linux-bcache, linux-btrfs, linux-f2fs-devel, linux-fsdevel, linux-raid, linux-scsi, linux-xfs, lkml, ocfs2-devel
Subsystem:
block layer, the rest, xen block subsystem, xen hypervisor interface · Maintainers:
Jens Axboe, Linus Torvalds, Roger Pau Monné, Juergen Gross, Stefano Stabellini
From: Mike Christie <redacted> The last patch added a REQ_OP_FLUSH for request_fn drivers and the next patch renames REQ_FLUSH to REQ_PREFLUSH which will be used by file systems and make_request_fn drivers so they can send a write/flush combo. This patch drops xen's use of REQ_FLUSH to track if it supports REQ_OP_FLUSH requests, so REQ_FLUSH can be deleted. v7: - Fix feature_flush/fua use. v6: - Dropped parts of patch handled by Jens's QUEUE_FLAG_WC/FUA patches and modified patch to check feature_flush/fua bits. Signed-off-by: Mike Christie <redacted> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Juergen Gross <redacted> --- drivers/block/xen-blkfront.c | 47 ++++++++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 23 deletions(-)
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index f01691a..d6429e7 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c@@ -196,6 +196,7 @@ struct blkfront_info unsigned int nr_ring_pages; struct request_queue *rq; unsigned int feature_flush; + unsigned int feature_fua; unsigned int feature_discard:1; unsigned int feature_secdiscard:1; unsigned int discard_granularity;
@@ -763,19 +764,14 @@ static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *ri * implement it the same way. (It's also a FLUSH+FUA, * since it is guaranteed ordered WRT previous writes.) */ - switch (info->feature_flush & - ((REQ_FLUSH|REQ_FUA))) { - case REQ_FLUSH|REQ_FUA: + if (info->feature_flush && info->feature_fua) ring_req->operation = BLKIF_OP_WRITE_BARRIER; - break; - case REQ_FLUSH: + else if (info->feature_flush) ring_req->operation = BLKIF_OP_FLUSH_DISKCACHE; - break; - default: + else ring_req->operation = 0; - } } ring_req->u.rw.nr_segments = num_grant; if (unlikely(require_extra_req)) {
@@ -866,9 +862,9 @@ static inline bool blkif_request_flush_invalid(struct request *req, { return ((req->cmd_type != REQ_TYPE_FS) || ((req->op == REQ_OP_FLUSH) && - !(info->feature_flush & REQ_FLUSH)) || + !info->feature_flush) || ((req->cmd_flags & REQ_FUA) && - !(info->feature_flush & REQ_FUA))); + !info->feature_fua)); } static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
@@ -985,24 +981,22 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, return 0; } -static const char *flush_info(unsigned int feature_flush) +static const char *flush_info(struct blkfront_info *info) { - switch (feature_flush & ((REQ_FLUSH | REQ_FUA))) { - case REQ_FLUSH|REQ_FUA: + if (info->feature_flush && info->feature_fua) return "barrier: enabled;"; - case REQ_FLUSH: + else if (info->feature_flush) return "flush diskcache: enabled;"; - default: + else return "barrier or flush: disabled;"; - } } static void xlvbd_flush(struct blkfront_info *info) { - blk_queue_write_cache(info->rq, info->feature_flush & REQ_FLUSH, - info->feature_flush & REQ_FUA); + blk_queue_write_cache(info->rq, info->feature_flush ? true : false, + info->feature_fua ? true : false); pr_info("blkfront: %s: %s %s %s %s %s\n", - info->gd->disk_name, flush_info(info->feature_flush), + info->gd->disk_name, flush_info(info), "persistent grants:", info->feature_persistent ? "enabled;" : "disabled;", "indirect descriptors:", info->max_indirect_segments ? "enabled;" : "disabled;");
@@ -1621,6 +1615,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id) if (unlikely(error)) { if (error == -EOPNOTSUPP) error = 0; + info->feature_fua = 0; info->feature_flush = 0; xlvbd_flush(info); }
@@ -2315,6 +2310,7 @@ static void blkfront_gather_backend_features(struct blkfront_info *info) unsigned int indirect_segments; info->feature_flush = 0; + info->feature_fua = 0; err = xenbus_gather(XBT_NIL, info->xbdev->otherend, "feature-barrier", "%d", &barrier,
@@ -2327,8 +2323,11 @@ static void blkfront_gather_backend_features(struct blkfront_info *info) * * If there are barriers, then we use flush. */ - if (!err && barrier) - info->feature_flush = REQ_FLUSH | REQ_FUA; + if (!err && barrier) { + info->feature_flush = 1; + info->feature_fua = 1; + } + /* * And if there is "feature-flush-cache" use that above * barriers.
@@ -2337,8 +2336,10 @@ static void blkfront_gather_backend_features(struct blkfront_info *info) "feature-flush-cache", "%d", &flush, NULL); - if (!err && flush) - info->feature_flush = REQ_FLUSH; + if (!err && flush) { + info->feature_flush = 1; + info->feature_fua = 0; + } err = xenbus_gather(XBT_NIL, info->xbdev->otherend, "feature-discard", "%d", &discard,
--
2.7.2